Method for regulating plant growth

ABSTRACT

SUBSTITUTED SUCCINAMIC AMIDES AND ANILIDES ARE USED TO REGULATE THE GROWTH OF PLANTS.

United States Patent 01 fice Patented Sept. 18, 1973 ABSTRACT OF THEDISCLOSURE Substituted succinamic amides and anilides are used toregulate the growth of plants.

This is a division of application Ser. No. 641,161, filed May 25, 1967now US. Pat. No. 3,632,646.

This invention relates to new compounds and their use as plant growthregulants.

The compounds of the invention may be represented by the formula:

Cliz-Hl-NHN wherein R and R may be an alkyl group having from 1 to 12carbon atoms, or, along with the nitrogen, form a non-aromaticheterocyclic ring, such as, l-pyrrolidyl, l-piperidyl or 4-morpholiny1;and R and K, may be hydrogen, an alkyl group having 1 to 12 carbonatoms, or compositely, along with the nitrogen atom, form a nonaromaticheterocyclic ring. Furthermore, where R, is hydrogen, R may also behydroxyalkyl, aminoalkyl, amino, R'NHCO- where R' is hydrogen or a loweralkyl group having from 1 to 6 carbon atoms, or where R is an aryl orsubstituted aryl group wherein the aryl group is phenyl or naphthyl andthe substitutions may be from 1 to 3 halogen, lower alkoxy, phenoxy,lower alkyl, aryl, cyano, carboxyl, hydroxyl or nitro groups. Thepreferred substituents being those which are orthopara directors andsubstituted at the ortho and para positions.

Examples of R and R are: methyl, isopropyl, isobutyl, octyl, dodecyl,and compositely R and R represent tetramethylene, pentamethylene andB-oxydiethylene. Examples of R are hydroxypropyl, N-dimethylamino ethyl,2- naphthyl, 2-iodophenyl, 2-isopropylphenyl, 4-methoxyphenyl,2-chloro-6-methylphenyl, 2,4-dichlorophenyl, 2 dimethylaminophenyl,Z-hydroxyphenyl, 2-cyanophenyl, 2-carbomethoxyphenyl, 2-acetoxyphenyl.

The compounds of the present invention may be prepared by either of twomethods. The first involves preparation through the imide by reactionwith an equimolar amount of amine or hydrazine using an inert solvente.g. benzene, acetonitrile.

RZi 41 IH In these cases the following procedure is preferable. In thisprocedure the N-R substituted imide is prepared according to proceduresknown to those experienced in the art. This imide is then reacted withthe desired hydrazine.

O 0 /R A CHE-"A NHN CH R1R2NNH2 2 NR3 Ra CHgC g CH ICN\ The amount ofhydrazine required is dependent upon the nature of R and may vary fromequimolar amounts to a 3 fold excess. The reaction may be carried outwithout any solvent or in any inert solvent, such as acetonitrile, orbenzene. The preferred solvents being those in which the imide is atleast slightly soluble. The reaction time varies from 3 hours to 1 daydepending upon the nature of R R NNH and R EXAMPLE IN-dimethylaminosuccinamide To 7.1 g. (.05 mole) ofN-dimethylaminosuccinimide of M.P. 56-57 C. were added 10 g. of 27%aqueous ammonia. The mixture was agitated and after a few minutes thesolid dissolved; thereafter the solution rapidly set to a mass of whitecrystals. After adding 10 ml. of ethanol, the mixture was heated to 65C. causing complete solution of the solid. Upon cooling this solution inan ice bath there precipitated 5.0 g. of N-dimethylaminosuccinamide aswhite crystals of M.P. 192193 C.

EXAMPLE II N-dimethylamino-N-phenylsuccinamide To 17.5 g. (.10 mole) ofN-phenylsuccinimide of M.P. 153 C. were added 30 g. (.50 mole) of1,1-dimethylhydrazine. After 18 hours of refluxing a clear solution hadformed. Upon removal of the excess dimethylhydrazine by distillation,the residue set to a white, crystalline solid. After slurrying withether and collecting the solid by filtration, 22.5 g. (96%) of colorlesscrystals of M.P. 154.-156 C. were obtained. When mixed with a sample ofN-phenylsuccinimide a melting range of 128-136 C. was obtained. Uponrecrystallization from acetonitrile colorless crystals of M.P. 154156 C.were obtained.

EXAMPLE III N-dimethylamino-N-methylcarbamylsuccinamide By reactingsuccinamide with methylisocyanate there was preparedN-methylcarbamylsuccinamide of M.P. 15 3- 155 C. (d). To a mixture of15.6 g. (.10 mole) of this compound and 40 g. of acetonitrile was added6.0 g. (.10 mole) of 1,1-dimethylhydrazine. After keeping the resultingsolution at room temperature for 15 minutes there formed a crystallineprecipitate. After standing for an additional 1 hour this mixture wascooled in an ice bath. Filtration gave 13 g. of white crystals of M.P.172- 174 C. A sample recrystallized from acetonitrile gave M.P. 177179C.

EXAMPLE IV N-dimethylamino-N'- (2-chlorophenyl succinamide (A) To 10.5g. (0.05 moles) of N-(2-chlorophenyl) succinimide, M.P. 110-112 C., wasadded 20 ml. (15.6 g. 0.26 moles) of 1,1-dimethylhydrazine. The mixturewas refluxed overnight. The solid was filtered to yield 8.3 g. whitepowder M.P. 141l42.5 C. An infrared spectrum showed peaks at 6.0011. and6.09,.

EXAMPLE V A representative list of compounds prepared by these methodsand representative of compounds of the present invention are shown inTable I. All give infrared spectra with two strong bands or one broadband in the 6.0-6.2

t the seed or crop rows will be from 0.1 to pounds per acre, applied tothe crop rows, the equivalent of an area 2" wide and 2" deep to parallelrows in one direction a distance of apart. Also, as a soil treatment thechemical may be applied broadcast as a similar dust or aqueous spraywith an application rate of 1.0 to 100 pounds per acre.

The chemicals of the invention are effective growth regulants and areparticularly useful for retarding the vegetative growth of plants byshortening their internodes. The growth regulant activity of thechemicals is of particular interest in connection with retardation ofvegetative growth of fruit trees without decreasing fruit size.Furthermore, the activity of these chemicals is of region indicative ofamides and hydrazides. 15 interest for producing other beneficialeffects on fruit such TABLE I Analysis (percent) Calculated FoundEmpirical R R R; Br M.P.,C. formula C H N 01 C H N Cl Methyl" MethylOrtho-ehlorophenyL 148-51 CrzHiuNaOQCl 53.43 5. 93 15.62 13.16 53.68 D dPhenyl 155-56 C12H17N302 61.26 7.28 17.86 61.22

do Hydrogen 195-7 CeHmNzOz 45. 27 8.23 do Ortho- 137-8 CuHnNaOa 60.20 7.58

ethoxyphenyl. Do do Methyl Methyl 73-4 CgHflNaO: 51. 32 9.15Pentamethylene Ortho- Hydrogen..- 179-80 CLSHZONKOZGI 58.14 6.51

chlorophenyl. Methyl Methyl. Ortho-fiuorophenyldo 131. 5-325 CrzHnNaOzF6 Do do Ethyl 154-7 Do do .'Hydroxyethyl Do do N-dimethylamlnodoPara-ethoxyphenyl Meta-chlorophenyL. Para-ehlorophenyL.2,6-diehlorophenyl...

Do do Parahydroxyphenyl. do.. Alpl1a-naphthyl (10.. Ortho-nitrophenyL.

bromophenyl.

chemical by incorporating the chemical in the soil before or afterplanting the seeds. The chemicals may be applied to plants in an inertmedium as dust in admixture with a powdered solid carrier, such as thevarious mineral silicates, e.g., mica, talc, pyrophyllite and clays oras an aqueous composition. The chemicals may be applied in admixturewith small amounts of surface-active wetting agents, which may beanionic, non-ionic, or cationic surface-active agents, generally asaqueous compositions. The chemicals may be dissolved in organic solventssuch as acetone, and the solutions of the chemicals emulsified in waterwith the aid of surface-active agents. Such surface-active agents arewell known and reference is made to US. Pat. No. 2,547,724, columns 3and 4 for detailed examples of the same. The chemicals of the inventionmay be admixed with powdered solid carriers, such as mineral silicates,together with a surface-active agent so that a wettable powder may beobtained which may be applied directly to plants, or which may be shakenup with water for application to the plants in that form.

As a foliar spray the chemicals may be applied to growing plants at arate of 0.01 to 10 pounds per acre. Such application is generally as anaqueous spray which also contains as noted above, a surface-activedispersing agent and a powdered solid carrier.

As a soil treatment the amount of the chemical applied as color,stop-drop, prolonged harvesting period, increased storageability,overcoming juvenility and return blossoming. Another beneficial growthregulant effect of interest in connection with retardation of vegetativeplant growth is inducing resistance to frost, smog drought and salinity.

The effectiveness of the chemicals of the present invention as plantgrowth regulants is illustrated in the following examples using growthretardation as criterion for activity.

EXAMPLE A This example illustrates the treatment of growing plants withthe chemicals of the present invention.

Water solutions or dispersions of the chemicals were prepared containing5000 parts per million (p.p.m.) of various chemicals of the inventionand 300 p.p.m. of a surface-active wetting agent (polyoxyethylenesorbitan monolaurate) which is known to be inactive in the tests run.

Peanut plants in the 2 to 3 leaf stage were sprayed to run off withaqueous compositions prepared as above containing 5000 p.p.m. ofcompound. The treated plants and untreated control plants were thenplaced in a chamber having humidity and a temperature of 75 F. After 24hours, they were taken out and placed in a greenhouse. The plants wereexamined four weeks after the application of the chemicals. The growthregulant effect was recorded by measuring the length of the internodesof the peanut plants. The results are calculated and expressed inpercent growth retardation as compared to the untreated check. They areshown in Table II:

TABLE IL-GROWTH nn'rgigg armN IN PEANUT SPRAY Other crops such assoybeans, pinto beans, apple trees and chrysanthemum show similar growthretardation on treatment with the chemicals of the present invention.

EXAMPLE B This example illustrates the growth regulant effect on plantsgrown in soil which has been treated with compounds of the presentinvention.

256 mg. of chemical were thoroughly mixed in a glass jar with two poundsof clean, dry sand. The mixing was accomplished by vigorously shakingthe jar which was covered with a screwcap. This masterbatch was thenthoroughly mixed with 12 pounds of soil to give a 40 ppm. concentrationin the sand soil mixture. The treated soil was then placed into 12 ouncestyrofoam cups. Three peanut seeds, Virginia Runner variety, wereplanted in each cup 2 weeks after soil incorporation of the chemicalusing 3 replicates for each treatment. An untreated check replicatedthree times in which seeds were planted at the same time Withoutchemical treatment was included in the test. The pots were thentransferred to the greenhouse, kept warm and moist maintaining agreenhouse temperature of 75-85 F. Four weeks after planting the growthof the peanut plant was measured, i.e., the distance from the node ofthe first true leaf to the uppermost leaf stipule. The results areexpressed as percent growth retardation as compared with the untreatedcheck plants (Table III).

TABLE III.-GROWTH RETARDATION 0F PEANUT PLANTS IN SOIL INCORPORATIONTESTS This example illustrates the growth regulant effect on apple treeswithout fruit size reduction.

Spray solutions containing 2000 ppm. active chemical were sprayed onyear old McIntosh apple trees using one gallon per tree and 2 trees pertreatment. Check trees without chemical treatment and trees sprayed withsuccinic acid 2,2-dimethylhydrazide were included in the test. Theapplications were made approximately 2 weeks after full bloom.Measurement on the new growth or shoots on the branches were taken 7weeks later measuring the distance from the growth present at the timeof spray to the tip of the shoot. Five shoots per tree were measured.The fruit was harvested and evaluated for size differences.

The results showing the length of the shoot growth and size of theapples is shown in Table IV.

TABLE IV.APPLE SPRAY TEST Shoot Apple size (inches) Sueeiuic acid 2,2dimethylhydrazide. 4. 6 3 10 22 9 N -d1methyIamino-N (2-chlorophenyl)succinamide 7. 6 6 38 Control- 17. 4 13 31 Having thus described ourinvention, what we claim and desire to protect by Letters Patent is:

1. A method of regulating plant growth comprising applying to the plantsor to the soil in which the plants grow, in an amount effective toregulate growth, a compound having the formula:

wherein R and R are alkyl groups or, compositely with the nitrogen, forma l-pyrrolidyl, l-piperidyl or a 4-morpholinyl ring; and R and R arehydrogen, an alkyl group, or, compositely with the nitrogen atom, form al-pyrrolidyl, l-piperidyl or a 4-morpholinyl ring; or, where R; ishydrogen, R is:

hydroxylalkyl,

N-dimethylaminoalkyl,

amino,

R'NHCO, where R is hydrogen or a lower alkyl, phenyl,

naphthyl,

substituted phenyl or naphthyl,

wherein the substituents are from 1 to 3 halogen, lower alkoxy, phenoxy,lower alkyl, phenyl, naphthyl, cyano, carboxyl, carbomethoxy, acetoxy,hydroxyl, or nitro groups;

the aforesaid alkyl, hydroxyalkyl and aminoalkyl groups having from 1 to12 carbon atoms and the aforesaid lower alkyl and alkoxy groups havingfrom 1 to 6 carbon atoms.

2. The method of claim 1 wherein R and R are methyl.

3. The method of claim 1 wherein R is hydrogen and R is a phenyl grouphaving a halogen, lower alkoxy, phenoxy, lower alkyl, phenyl, cyano,carboxyl, hydroxyl, or nitro substitution.

4. The method of claim 1 wherein the substitution on the phenyl group ison the orthoor para-position.

5. The method of claim 1 wherein R and R are methyl, R is hydrogen and Ris 2-chlorophenyl.

6. The method of claim 1 wherein R and R are methyl, R is hydrogen and Ris o-tolyl.

7. The method of claim 1 wherein R and R are methyl, R is hydrogen and Ris o-ethoxyphenyl.

References Cited UNITED STATES PATENTS 3,240,799 3/1966 Hageman et al.71-76 3,257,414 6/1966 Hageman et al. 7176 JAMES O. THOMAS, JR., PrimaryExaminer US. Cl. X.R.

